/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 */
package org.apache.qpid.management.common.sasl;

import org.apache.harmony.javax.security.auth.callback.Callback;
import org.apache.harmony.javax.security.auth.callback.CallbackHandler;
import org.apache.harmony.javax.security.auth.callback.NameCallback;
import org.apache.harmony.javax.security.auth.callback.PasswordCallback;
import org.apache.harmony.javax.security.auth.callback.UnsupportedCallbackException;
import java.io.IOException;

public class UserPasswordCallbackHandler implements CallbackHandler {
	private String user;
	private char[] pwchars;

	public UserPasswordCallbackHandler(String user, String password) {
		this.user = user;
		this.pwchars = password.toCharArray();
	}

	public void handle(Callback[] callbacks) throws IOException,
			UnsupportedCallbackException {
		for (int i = 0; i < callbacks.length; i++) {
			if (callbacks[i] instanceof NameCallback) {
				NameCallback ncb = (NameCallback) callbacks[i];
				ncb.setName(user);
			} else if (callbacks[i] instanceof PasswordCallback) {
				PasswordCallback pcb = (PasswordCallback) callbacks[i];
				pcb.setPassword(pwchars);
			} else {
				throw new UnsupportedCallbackException(callbacks[i]);
			}
		}
	}

	private void clearPassword() {
		if (pwchars != null) {
			for (int i = 0; i < pwchars.length; i++) {
				pwchars[i] = 0;
			}
			pwchars = null;
		}
	}

	protected void finalize() {
		clearPassword();
	}
}
